Air pump attachment for sewing machines



April 1948. w. o. RUNCIE 2,439,319 I AIR PUMP ATTACHMENT FOR SEWING MACHINES Filed Sept. 22, 1944 2 Sheets-Sheet 1 Y WORunaz' April 6, 1948. w. o. RUNCIE 'AIR PUMP ATTACHMENT FOR SEWING MACHINES 2 Sheet-Sheet 2 Filed Sept. 22, 1944 Patented Apr. 6, 1948 AIR PUMP ATTACHMENT FOR SEWING MACHINES Walter 0. Runcie, Lima, Peru Application September 22, 1944, Serial No. 555,343

T 8 Claims. 1

This invention relates to an attachment for a sewing machine which will supply pulsating air pressure to a darning attachment and is an improvement over the construction embodied in the copending application filed by myself and Geza M. Keczeli, Serial Number 469,462, filed December 18, 1942, for Darning attachment for sewing machines, now Patent No, 2,390,329, issued February 4, 1947.

An object of this invention is to provide an attachment of this kind which can be secured to the supporting rod for the presser foot of a sew ing machine and which may be coupled to the needle carrier so as to provide for pulsating air pressure.

Another object of this invention is to provide an attachment of this kind whicnis secured to the head of the'sewing machine above the table thereof and which can be attached and removed without interfering with or requiring any change in the present parts of the machine, except for removal of the presser foot.

A further object of this invention is to provide an improved pulsating air generating means together with means for regulating the amount of air pressure generated or developed without varying the stroke of the plunger or piston.

A further object of this invention is to provide in a device of this kind an improved supporting means which permits lateral adjustment of the cylinder at the front of the head.

With the above objects and others which may hereinafter appear, the invention consists of the novel construction, combination and arrangement of parts as will be more specifically referred to and illustrated in the accompanying drawings wherein are shown embodiments, but it is to be understood that changes, variations and modifications may be resorted to which fall within the tail taken through the attachment removed from the sewing machine.

' Figure 5 is a sectional view taken on the line 5-5 of Figure 1.

Figure 6 is a sectional view taken on the line 6--6 of Figure 4.

Figure '7 is a longitudinal section of a modified form of cylinder construction.

Referring to the drawings, the numeral l0 designates generally the head of a sewing machine which has a vertically reciprocating needle carrier II slidably mounted therein and a vertically adjustable foot carrying rod or shaft I2. A cylinder I4 is disposed on the end of the head ID in a vertical position and includes a lower head l3 which is threaded onto the lower endof the cylinder M. A nut I5 is threaded onto a stud 16 which is carried by the head l3, and a slotted disc I1 is interposed between the nut l5 and the adjacent face of the head l3. A supporting arm i8 is integral with and extends angularly from the slotted disc I! and is provided at its lower end with a vertical U-shaped clamp IS. The clamp I9 is adapted to engage the lower end of the foot supporting member 12, and a clamping screw 29 which is threaded into the supporting member I2 tightly holds the U-shaped member 19 on the lower end of the foot carrying member 12.

The cylinder [4 has slidably mounted therein a plunger or piston 2| and the latter as here shown includes a cup-shaped flexible member 22 which is interposed between a pair of plates 23 and 24 mounted on the upper end of a piston rod 25. The retaining member 24 is preferably in the form of a nut which is threaded onto the upper reduced end 26 of the piston or plunger rod 25. The cylinder l4 adjacent the lower end thereof is provided with a vent Opening 27 so as to provide for the inlet and outlet of air below the piston or plunger 2|.

An upper head 28 is carried by the upper end of the cylinder l4 and an adjustable cap 29 overlies the upper end of the cylinder Hi, there being a compression spring 30 between the head 28 and the inner side of the cap 29. A nipple 3| is threaded as at 32 into the head 28 and is formed above the head 28 with a laterally extending opening 33. The cap 29 includes a tapered nipple 34 having an opening 35 which may be moved into or out of registry with the opening 3 3 so as to regulate the amount of air which is to be released from the nipple 3| during the reciprocation of the plunger or piston 2 I.

The lower end of the piston or plunger rod 25 has secured thereto a right angularly disposed arm 36 which extends towards the needle carrier II. The terminal end of the arm 36 has secured thereto an upwardly extending pin 31 which is inserted in the needle clamp 38 normally carried by the lower end of the needle carrier H. In this manner as the needle carrier II is vertically reciprocated, the piston or plunger 2| will also be reciprocated. The nipple 3| at its upper end is adapted to have engaged thereover one end of a flexible tube 39, the opposite end of the tube 39 being secured to a relooping needle apparatus, similar to that embodied in the copending application supra.

Referring now to Figure '7, there is disclosed a modified form of cylinder structure which in cludes a cylinder I 4a having a head or cap 29a formed integrally with the upper end thereof and the nipple 3m in this instance is also formed integral with the cap 23a. It will be understood that the remaining structure including the plunger and supporting means hereinbefore described will be used with the cylinder Ma. As

will be noted, the cylinder Ma is provided with a vent opening 27a adjacent the lower end thereof.

In the use and operation of this attachment, the adjustable cylinder 14 is secured in upright position by engaging the U-shaped clamp $9 with the low-er end of the presser foot carrier !2. The pin 31' is then inserted in the place normally occupied by the needle and held in position by the needle clamp 38. As the needle carrier H is vertically reciprocated piston or plunger 2! will move therewith and the air above the piston or plunger 2| will pass through the nipple 3| and the hose 39, to the relooping needle assembly. The pressure generated by the reciprocating plunger or piston 2! may be regulated by adjusting exhaust opening 35 with respect to opening 33.

As hereinabove stated, this attachment may be mounted on the present parts of the sewing machine readily, it being only necessary to remove the presser foot from the supporting member l2, and the needle normally used in sewing is removed from the clamp 38 and the pin 37 inserted in this clamp so that plunger 2! will reciprocate with movement of the needle carrier. The provision of the slotted disc I! permits lateral adjustment of cylinder it so that this attachment can be readily mounted on difierent types and makes of sewing machines.

What I claim is:

1. An air pump for attachment to a sewing machine which has a presser foot shaft and a reciprocating needle carrier, comprising a cylinder having an outlet at one end, a piston slidable in said cylinder, a supporting arm carried by the opposite end of said cylinder for attachment to a presser foot shaft to thereby support said cylinder solely from the presser foot shaft, and means connected to said piston and extending laterally therefrom for connecting said piston to a needle carrier whereby said piston will be reciprocated y said needle carrier. 7

2. An air pump as set forth in claim 1 including means regulating the air pressure generated by reciprocation of said piston.

3. An air pump as set forth in claim 1 wherein said latter connecting means includes an upwardly extending pin engageable in the needle holder of the needle carrier.

4. An air pump for attachment to a sewing machine which has a presser foot shaft and a reciprocating needle carrier, comprising a cylinder. a piston slidable in said cylinder, a piston rod secured to said piston and extending from an end of said cylinder, a supporting arm carried by said cylinder for attachment to a presser foot shaft to thereby support said cylinder from the presser foot shaft, a second arm fixed to and extending right angularly from said piston rod, and an upstanding pin carriedby second arm for removable attachment to a needle carrier and for operation therewith.

5. A pulsating air pump for attachment to a sewing machine which has a presser foot shaft and a reciprocating needle carrier, comprising an upright cylinder, a head on the lower end of said cylinder, a threaded stud carried by said head having a central bore, a supporting arm for said cylinder, a ring carried by one end of said arm formed with an elongated opening through which said stud loosely and adjustably engages, a nut threaded on said stud securing said ring and stud tog-ether, means releasably securing the other end of said arm to a presser foot shaft for supporting said cylinder solely from the presser foot shaft, a piston slidable in said cylinder, a piston rod secured to said piston and slidable through said stud, an angularly disposed arm secured to said piston rod, an upstanding pin carriedby said latter arm for releasable engagement with a needle carrier for operation thereby, and means at the upperend of said cylinder for coupling the latter to a driven element. a

6. An air pump as set forth in claim 5 wherein said latter named means includes an adjustable air release means whereby the air may be selectively discharged into the atmosphere.

7. An air pump for attachment to a sewing machine he'ad having a needle carrier and a pressure foot shaft, comprising a cylinder, a piston reciprocating in said cylinder, meansconnecting said piston with the'needle carrier of a head for operation thereby, and means supporting said cylinder laterally of a head, said supporting means including a supporting arm for attachment to the presser foot shaft, a ring carried by said arm formed with an elongated opening, a threaded stud carried by said cylinder engaging through said opening, and adjustable lengthwise thereof, and a clamping nut threaded onto said stud.

8. A pulsating air pump for attachment to a sewing machine which has a presser foot shaft and a reciprocating needle carrier, comprising an upright cylinder, a head on the lower end of said cylinder, a threaded stud carried by said head having a central bore, a supporting arm for said cylinder, a ring carried by one end of said arm formed with an elongated opening through which said stud loosely and adjustably engages, a nut threaded on said stud securing said ring and stud together, a Piston slidable in said cylinder, a piston rod secured to said piston and slidable through said stud, an angularly disposed arm secured to said piston rod, an upstanding pin carried by said latter arm for releasable engagement with a needle carrier for operation thereby, means at the upper end of said cylinder for coupling the latter to a driven element, and means securing said arm on the machine in a position whereby said pin will be in alignment with the needle carrier.

WALTER O. RUNCIE.

shenan ans CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS' 

